The present invention relates to a new and distinct Coreopsis given the cultivar name ‘TNCORSG’. Coreopsis is in the family Asteraceae. This new cultivar originated from a controlled breeding program to produce hardy compact Coreopsis. The new cultivar originated from a planned cross of two proprietary unnamed Coreopsis verticillata hybrid seedlings. The new cultivar of Coreopsis is an herbaceous perennial to be grown for landscape and container use in a sunny site. The trademark designation is ‘Sunstar™ Gold’
Compared to Coreopsis ‘Bengal Tiger’, U.S. Plant Pat. No. 25,345, the new cultivar has a larger, denser habit with more crowns.